Cage of Larkspur

An orphan named Noah is tricked by a friend and ends up being sold in an auction. The man who successfully bid on him for two hundred million was Gilbert, an entrepreneur rumored to be cruel and merciless. Noah is sure he would be treated terribly, but instead, he is taught the pleasures he had never known through having sex for the first time. He wanted to go home so badly, but after feeling Gilbert's awkward kindness and finding out the true reason for buying him, Noah's determination to escape wavers...

(Source: MangaPlaza)

Note: Includes one extra chapter.